The present invention relates to a vehicle external recognition system and a related method and, more particularly, to a vehicle external recognition system and its related method wherein a relative position between a forward object present ahead of an own vehicle and the own vehicle is detected and, based on this relative position, a relative velocity between the forward object and the own vehicle is calculated, thereby detecting a motion state of the forward object.
Japanese Patent Application Laid-Open Publication No. 9-159759 discloses a device arranged to detect a forward object present ahead of an own vehicle for thereby detecting a motion state of the forward object. In particular, this device is configured such that a relative velocity between the captured forward object and the own vehicle is calculated and, on this occasion, if a calculated relative velocity lies within a given range determined by the speed of the own vehicle and such a resulting status can be continuously obtained from a past history, then the captured forward object is determined as a forward preceding vehicle and on the other hand, the rest is determined as a stationary object.